A curved battery could be in store for a future iPhone or iPad.Photo by Apple/USPTO

Apple is eyeing different shapes for batteries to find more room for them in phones, tablets, and other mobile gadgets.

Published today by the U.S. Patent and Trademark Office, a patent application dubbed "Curved battery cells for portable electronic devices," describes exactly that. The shape of such a battery would be changed during the manufacturing process to form a curve in its design. That trick would be achieved by heating up a set of curved plates and applying pressure to the battery cell.

The goal would be to create a battery that can make better use of available space in a small mobile device. Instead of taking up one single chunk of real estate, the end of a curved battery could snake around the edges or certain internal components to find a spot for itself. As the patent filing explains it:

For example, the curve may be formed at one or more ends of the battery cell to allow the battery cell to occupy a curved and/or rounded space within the enclosure of a laptop computer, tablet computer, mobile phone, personal digital assistant (PDA), digital camera, portable media player, and/or other type of battery-powered electronic device.

Shaving off a couple of layers could result in a battery with a rounded corner or simply a thinner battery, as explained in the patent filling:

In some embodiments, the non-rectangular shape includes two or more thicknesses. For example, the two or more thicknesses may be created by removing material from the bottom and/or side of the cathode and/or anode to allow the battery cell to gradually decrease in thickness from one end to another.

Again, the goal is to better squeeze a battery into the limited space inside a mobile device. That goal becomes more important as Apple seeks to make new iPads and other devices thinner than the previous models.

And Apple is hardly alone. Other companies have also looked into designing curved and flexible batteries that could find a niche for themselves in today's mobile market. Scientists across several universities recently revealed the design of a battery that can stretch up to 300 percent beyond its normal size, according to an article in Nature Communications.